Preconcentration and Determination of Perfluoroalkyl Substances (PFASs) in Water Samples by Bamboo Charcoal-Based Solid-Phase Extraction Prior to Liquid Chromatography-Tandem Mass Spectrometry.

In this work, bamboo charcoal was used as solid-phase extraction adsorbent for the enrichment of six perfluoroalkyl acids (PFAAs) in environmental water samples before liquid chromatography-tandem mass spectrometry analysis. The specific porous structure, high specific surface area, high porosity, and stability of bamboo charcoal were characterized. Several experimental parameters which considerably affect extraction efficiency were investigated and optimized in detail. The experimental data exhibited low limits of detection (LODs) (0.01-1.15 ng/L), wide linear range (2-3 orders of magnitude and R ≥ 0.993) within the concentration range of 0.1-1000 ng/L, and good repeatability (2.7-5.0%, n = 5 intraday and 4.8-8.3%, n = 5 interday) and reproducibility (5.3-8.0%, n = 3). Bamboo charcoal was successfully used for the enrichment and determination of PFAAs in real environmental water samples. The bamboo charcoal-based solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry analysis possessed great potential in the determination of trace PFAA levels in environmental water samples.

Metal-organic framework MIL-53(Al) as a solid-phase microextraction adsorbent for the determination of 16 polycyclic aromatic hydrocarbons in water samples by gas chromatography-tandem mass spectrometry.

In this paper, the potential applications of metal-organic framework (MOF) materials as fiber coatings for the solid-phase microextraction (SPME) of polycyclic aromatic hydrocarbons (PAHs) in water samples were explored. Fibers coated with MIL-53(Al, Cr, Fe) materials were fabricated by an adhesive method for SPME. The quantitation was performed by gas chromatography-tandem mass spectrometry (GC-MS/MS) using the multiple reaction monitoring mode. Among the three MIL-53(M) coatings, MIL-53(Al) showed the highest extraction efficiency towards PAHs under the current fabrication procedure. Under optimized conditions, the MIL-53(Al)-coated fiber showed good precision (relative standard deviation <12.5%), low detection limits (0.10 ng L(-1) to 0.73 ng L(-1), S/N = 3), and good linearity (R(2) > 0.98) for aqueous solutions containing 16 PAH . The fiber also offered high thermal and chemical stability. The method developed based on MIL-53(Al) SPME-GC-MS/MS was successfully applied in the analysis of real water samples. Based on the simulation results, the PAHs were adsorbed on MIL-53(Al) primarily through the hydrophobic and π-π interactions between PAHs and the organic linker of the material. The results presented in this paper indicate that water-stable MOF materials have great potential for the SPME of aromatic compounds in water samples.

Rapid analysis of polybrominated diphenyl ethers in soil by matrix solid-phase dispersion using bamboo charcoal as dispersive sorbent.

An expeditious and sensitive method for the analysis of eight major polybrominated diphenyl ethers (PBDEs) in soil is presented in this study. The method is based on matrix solid-phase dispersion (MSPD) extraction and gas chromatography with negative chemical ionization mass spectrometry. Bamboo charcoal, a cheap and potentially useful material, was selected for the first time as the MSPD dispersive sorbent. Parameters affecting the extraction efficiency, including the ratio of sorbent to sample, and the type and amount of eluent, were investigated and optimized in detail. Under optimal conditions, the spiked recovery of the PBDEs was in the range 71.7-105.9%, and the limits of detection varied from 10 to 400 pg g(-1) (dry weight). Excellent linearity with correlation coefficients (r(2)) of 0.9992-0.9999 was obtained over the concentration range of 0.10-500 ng g(-1) , except for BDE-209, for which the effective concentration range was 1.0-5000 ng g(-1) . The developed method has been successfully applied to the analysis of PBDEs in real soil samples.

Ionic liquid/ionic liquid dispersive liquid-liquid microextraction.

In this article, a novel and simple microextraction method, termed ionic liquid/ionic liquid dispersive liquid-liquid microextraction (IL/IL-DLLME), has been designed and developed for the rapid enrichment and analysis of environmental pollutants. Instead of using hazardous organic solvents, two kinds of ILs, hydrophobic IL and hydrophilic IL, were used as extraction solvent and disperser solvent in IL/IL-DLLME step, respectively. Permethrin and biphenthrin, two of the often-used pyrethroid pesticides, were used as model compounds. Factors that may affect the enrichment efficiencies were investigated and optimized in detail. Under optimum conditions, permethrin and biphenthrin exhibited a wide linear relationship over the range 1-100 µg/L. For permethrin and biphenthrin, the precisions were 4.65-7.78%, and limits of detection were found to be 0.28 and 0.83 µg/L, respectively. Satisfactory results were achieved when the present method was applied to analyze the target compounds in real-world water samples with spiked recoveries over the range 84.1-113.5%. All these facts indicated that IL/IL-DLLME is a simple and rapid alternative for the enrichment and analysis of environmental pollutants and will have a wide application perspective in the future.

Application of liquid-phase microextraction and gas chromatography-mass spectrometry for the determination of chloroform in drinking water.

In this paper, a novel method for the determination of chloroform in drinking water has been described. It is based on liquid-phase microextraction (LPME) and gas chromatography-mass spectrometry (GC-MS). Extraction conditions such as solvent selection, organic solvent dropsize, stirring rate, content of NaCl and extraction time were found to have significant influence on extraction efficiency. The optimized conditions were 1.5 microl xylene, 20 min extraction time at 400 rpm stirring rate without NaCl addition. The linear range was 1.0 - 100 microg l(-1) for chloroform. The limit of detection (LOD) was 1.0 microg l(-1); and relative standard deviation (RSD) at the 30 microg l(-1) level was 2.9%. Tap water samples from a laboratory were successfully analyzed using the proposed method. The relative recovery of spiked water samples was 104%.

Carboxylated solid carbon spheres as a novel solid-phase microextraction coating for sensitive determination of phenols in environmental water samples.

The high performance separation and enrichment of polar phenols from aqueous matrices is often difficult due to the strong interactions between phenols and water. In this paper, carboxylated solid carbon spheres (SCSs-COOH) were, for the first time, used as a novel coating material in the solid-phase microextraction (SPME) of polar phenols at ultra-trace levels in environmental water samples. Gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) was applied for sample quantification and detection. The novel SCSs-COOH-coated fiber exhibited good thermal stability (>330 °C) and higher extraction efficiency than commercial fibers in the extraction of phenols. The Plackett-Burman design was employed to optimize the extraction factors affecting the extraction efficiency through a response surface methodology. A possible phenol extraction mechanism enabled by the SCSs-COOH-coated fiber is proposed. Under the optimized conditions, low detection limits (0.26-2.63 ng L(-1)), a wide linear range (1-1000 ng L(-1)), good repeatability (2.00-9.02%, n=5) and excellent reproducibility (2.08-8.55%, n=3) were achieved. The developed method was validated against several environmental water samples, with satisfactory results being obtained each case.

Application of bamboo charcoal as solid-phase extraction adsorbent for the determination of atrazine and simazine in environmental water samples by high-performance liquid chromatography-ultraviolet detector.

In this article, a new method for the determination of triazine herbicides atrazine and simazine in environment aqueous samples was developed. It was based on solid-phase extraction (SPE) using bamboo charcoal as adsorbent and high-performance liquid chromatography-ultraviolet detector (HPLC-UV) for the enrichment and determination of atrazine and simazine at trace level. Related important factors influencing the extraction efficiency, such as the kind of eluent and its volume, flow rate of the sample, pH of the sample, and volume of the sample, were investigated and optimized in detail. Under the optimal conditions, the experimental results showed that excellent linearity was obtained over the range of 0.5-30 microg L(-1) with correlation coefficients 0.9991 and 0.9982, for atrazine and simazine, respectively; and the relative standard deviations of two analytes were 8.3, 8.7%, respectively. The proposed method was successfully applied to the analysis of tap water and well water samples. And satisfactory spiked recoveries were obtained in the range of 75.2-107.1%. The above results indicated that the developed method was an excellent alternative for the routine analysis in environmental field.

Sensitive measurement of ultratrace phenols in natural water by purge-and-trap with in situ acetylation coupled with gas chromatography-mass spectrometry.

A novel purge-and-trap method coupled with gas chromatography-mass spectrometry (GC-MS) is developed for the analysis of trace and ultratrace phenols based on their derivatization with acetic anhydride. Parameters affecting the extraction efficiency, such as purge temperature, concentration of sodium chloride, purge time, and volume of derivatization reagent, were investigated. The optimized conditions were addition of 150 microL acetic anhydride, purge time of 25 min at the purge temperature of 60 degrees C with 30% NaCl. The linear range was 0.2-100 microg L(-1) for phenols. The limits of detection (LODs) ranged from 0.08 to 0.15 microg L(-1) and the relative standard deviations (RSDs) for most of the phenols at the 10 microg L(-1) level were below 10%. Natural water samples collected from a pool were successfully analyzed using the proposed method. The recovery of spiked water samples was 72.9-84.2%.